The present invention relates to an inflatable restraint assembly useful within the interior of a transportation vehicle to cover a side portion of the vehicle interior adjacent to an occupant to be protected during a collision event. More particularly, the invention relates to an air bag cushion deployable from a position over the door frame of the vehicle downwardly over a portion of the vehicle interior in a predetermined deployment path adjacent to the occupant to be protected. The present invention also provides an air bag cushion which is inflatable downwardly from a storage position over the door frame of the vehicle over a broad expanse to the side of an occupant to be protected while substantially avoiding interference with any shoulder harness restraint which may be attached to the side portion of the vehicle interior.
It is well known in motor vehicles to provide air bag cushions for protecting a vehicle occupant during a collision event wherein such air bag cushions are in fluid communication with gas generating inflators so as to inflate the cushions upon sensing predetermined vehicle conditions such as deceleration exceeding a certain level. It is further known to provide air bag systems including inflatable restraint cushions which are deployed from positions of attachment along the roof rail portion of the vehicle frame above the doors of the vehicle such that the inflatable restraint cushion extends downwardly in substantially curtain-like fashion between the occupant to be protected and the side portions of the vehicle adjacent to such occupant. Such coverage is intended to provide cushioning restraint for the occupant during a side impact or an extended roll-over collision event.
It is believed to be generally desirable for a curtain-like side air bag cushion to be held in a substantially tensioned condition across the surface being covered so as to provide a well defined barrier between the occupant and the covered region. Such a condition is believed to be useful in holding the vehicle occupant within the vehicle during an extended roll-over event. In the past, it has been proposed to fixedly attach the lower edges of the curtain-like air bag cushions to opposing fixed positions along the vehicle frame below the roof rail. However, such a configuration may result in an excessive length of material extending along the lower edge of the curtain-like structure between the lower most points of attachment once deployment takes place.
The length of the lower edge of the cushion extending between points of attachment to the vehicle frame may be shortened to some degree through inflation of elongate gas receiving chambers running from the top of the curtain to the lower edge. However, such a technique to obtain the desired taut orientation over the covered area may require an excessive amount of material and labor in construction and may further require a larger quantity of inflation gas to inflate the cushion to the desired tensioned orientation than would otherwise be required to obtain the desired cushioning and restraining characteristics.
Prior curtain-like air bag cushions deployable from storage positions above the door frame have also been difficult to deploy over extended areas adjacent to the occupant to be protected due to interference from elements extending outwardly from the regions to be covered. In particular, in the event that such curtain-like cushions are intended to cover regions which include a shoulder harness attachment, the deployment of such a cushion structure may be obstructed by the shoulder harness assembly which thereby prevents the cushion from assuming a completely taut configuration along its lower edge.
This invention provides advantages and alternatives over the prior art by providing an inflatable restraint assembly including an inflatable curtain structure deployable from a storage position along the roof rail of the vehicle so as to extend downwardly over an area within the vehicle interior adjacent to an occupant to be protected. The inflatable curtain structure is operatively connected to a guide element which guides the inflatable curtain structure downwardly from its storage location along the roof rail of the vehicle and thereafter serves to anchor the curtain structure over the covered area in a substantially tensioned configuration. Due to the presence of the guide element, a separate fixed attachment between the lower edge of the inflatable curtain structure and the vehicle frame may be eliminated thereby simplifying the storage of the inflatable curtain structure prior to deployment.
According to one potentially preferred aspect of the present invention, an inflatable restraint assembly is provided including an inflatable curtain structure which may be deployed downwardly from a position of storage along the roof rail of the vehicle in covering relation over an area substantially between the xe2x80x9cAxe2x80x9d pillar and the xe2x80x9cBxe2x80x9d pillar of the vehicle frame with a tensioning guide element being disposed substantially over the xe2x80x9cBxe2x80x9d pillar such that the inflatable curtain structure travels downwardly from its storage position along the tensioning guide element and is thereafter held in tension between the xe2x80x9cAxe2x80x9d pillar and the guide element at the xe2x80x9cBxe2x80x9d pillar.
According to another potentially preferred aspect of the present invention, an inflatable restraint assembly is provided which includes an inflatable curtain structure which may be guided downwardly away from a storage position along the roof rail of the vehicle by a tensioning guide element in the form of an elongate lace structure in sliding engagement with the inflatable curtain structure such that during inflation the inflatable curtain structure travels downwardly along the elongate lace element. The inflatable curtain structure is thereafter anchored in static tension along its lower edge between the elongate lace element and a point of attachment on the vehicle frame to which-the other end of the lower edge of the curtain structure is attached. The inflatable curtain structure may be held in its full deployed position by a directional locking element disposed along the guide element which prevents curtain from retreating upwardly along the guide element following deployment.
According to another aspect of the present invention, an inflatable restraint assembly is provided including an inflatable curtain structure which may be guided downwardly away from a storage position along the roof rail of the vehicle by a tensioning guide element in the form of a tether accepting channel in sliding engagement with a tethering element fixedly attached to the inflatable curtain structure such that the tethering element slides downwardly along the tether accepting channel during deployment of the inflatable cushion and is thereafter held in tensioned relation within the channel once inflation is complete such that the inflatable curtain structure is stretched over a region between the tether accepting channel and an opposing point of attachment to the vehicle frame.
According to still a further potentially preferred aspect of the present invention, an inflatable restraint assembly is provided including an inflatable curtain structure of substantially segmented construction which may be deployed over an expanse between the xe2x80x9cAxe2x80x9d pillar and the xe2x80x9cCxe2x80x9d pillar of a vehicle frame substantially without encountering interference from a shoulder harness attached at an intermediate location between the xe2x80x9cAxe2x80x9d pillar and the xe2x80x9cCxe2x80x9d pillar. A single inflator may nonetheless be utilized to inflate such an inflatable curtain structure by maintaining a common inflation chamber in the region between the segmented sections of the curtain structure. The segmentation of the inflatable curtain structure permits each segment to be operatively connected to a travel guide element extending along the xe2x80x9cBxe2x80x9d pillar of the vehicle so as to permit the controlled downward deployment of the segmented curtain structure and the subsequent tensioned restraint along the lower edge of the inflatable curtain structure across the covered region.